Synthesis of sugar laurate esters via lid-designed lipase immobilized in magnetic nanoflower system

Sugar fatty acid esters, serving as multifunctional biosurfactants, are extensively utilized in food formulations for emulsification, foam stabilization, and microbial preservation. Enzymatic transesterification using lipases offers distinct advantages over chemical synthesis, including mild reaction conditions and reduced energy consumption. In this study, we engineered a cold-adapted lipase (Lip) through lid domain truncation and mutation, yielding the optimized variant Lip-8 to alleviate substrate channel steric hindrance, coupled with tannic acid-modified magnetic nanoflowers (TA-MNFs) via a one-pot immobilization strategy to create Lip-8/TA-MNFs. This immobilized enzyme demonstrated significantly enhanced catalytic performance, achieving a 12.91-fold activity increase compared to free lipase. Under optimized conditions (40 °C, 36 h), the system synthesized fructose laurate esters with 93.07 % conversion efficiency. Structural characterization confirmed the predominant formation of mono- and di-esters, which exhibit dual surfactant and emulsifying properties suitable for food-grade applications.